MRI of superior capsular reconstruction graft and associated short-term clinical outcomes in patients with massive irreparable rotator cuff tears.

OBJECTIVE

To assess MRI appearance of the dermal allograft and its correlation with clinical outcome following superior capsular reconstruction (SCR).

MATERIALS AND METHODS

This is a retrospective study of patients who underwent SCR between 2015 and 2018. Patients with postoperative MRI and clinical follow-up were included. Exclusion criteria were preoperative shoulder instability, advanced glenohumeral arthritis, and lack of postoperative MRI or clinical follow-up. Radiographs and MRIs were evaluated for graft integrity and position, acromiohumeral interval, superior subluxation distance (SSD), and glenohumeral cartilage loss. Correlation between imaging and clinical outcome measures were assessed.

RESULTS

24 shoulders (23 patients) met the inclusion criteria at a mean clinical and MRI follow-up of 9.1 months. There were 12 intact grafts (50%) and 12 torn grafts (50%), most commonly at the glenoid attachment (8/12). Patients with graft tear had greater SSD (mean 10.5 ± 6.1 mm) than those without tear (mean 6.1 ± 3.8 mm) (p = 0.028). SSD > 7.9 mm had a 79% sensitivity and 91% specificity for graft tear. The intact grafts were more commonly covering the superior humeral head (91.7%) compared with the torn grafts (41.7%) (p = 0.027). There was improvement of clinical outcome measures including American Shoulder and Elbow Surgeons score (p = 0.005) and forward elevation (p = 0.021) although there was no correlation between clinical outcome and integrity of the graft.

CONCLUSION

SCR results in significant short-term clinical improvement even in the presence of graft tear on postoperative MRIs on current study. Gap between graft and the anchors, non-superior position of the graft, and humeral head superior subluxation can be associated with tear.